The current MGA driver in the SVGA server supports the Matrox Millennium (MGA2064W) with Ti3026 RAMDAC. It has been tested with 175, 220MHz, and 250MHz cards with 2MB, 4MB and 8MB WRAM. It also supports, for the first time, Matrox Mystique (MGA1064SG) board tested up to 135 MHz for 2 and 4 MB configs.
NOTE: This driver is pretty new, and not everything works like you expect it to. It shouldn't crash your machine, but you may have video artifacts or missing lines. Please report any and all problems to XFree86@Xfree86.org using the appropriate bug report sheet.